A distinguishing feature of this trial is that, beyond validating a new screening method, participants may also have cancers actually detected at an early stage.
Lung Cancer: A Large-Scale Screening Trial
On May 18, 2026, the Assistance Publique–Hôpitaux de Paris (AP-HP) officially opened participation in the IMPULSION program, a national study aimed at evaluating the implementation of an organized lung cancer screening program in France. This project follows the recommendations issued in 2022 by the Haute Autorité de Santé, which encouraged the launch of trials to assess the feasibility of a large-scale screening system. Led by AP-HP and supported by the Hospices Civils de Lyon and the CHU of Nice, the research is funded with 6 million euros from the French National Cancer Institute (INCa). Its ambition is substantial: to recruit 20,000 volunteer participants to evaluate the conditions for a potential national rollout. Eligible are individuals residing in the Auvergne-Rhône-Alpes, Hauts-de-France, Île-de-France, Pays de la Loire, and Provence-Alpes-Côte d’Azur regions.
The IMPULSION program is currently being rolled out in Île-de-France, in Hauts-de-France, in Pays de la Loire, in Provence-Alpes-Coire d’Azur, and in Auvergne-Rhône-Alpes. It targets individuals at high risk due to tobacco exposure.
The primary objective is not yet to implement widespread screening. It is above all a research study to determine whether a national program can be organized effectively, both medically and economically. An integrated health-economics study is included in the protocol to compare the costs of screening with those of cancers diagnosed at late stage. This approach addresses a major public health issue. According to data reported by AP-HP, nearly 53,000 new cases of lung cancer are diagnosed each year in France, and about 30,900 people die from it. Even more concerning, 73% of cases are currently detected at an advanced stage, when treatment options are more limited.
Moreover, several international studies have shown that low-dose chest CT screening could reduce lung cancer-specific mortality by 20 to 25%. When combined with help for smoking cessation, this benefit could reach 38%.
The Lung Cancer Targeted by a Low-Dose CT Scan and the Support of AI
The chosen approach rests on a low-dose chest CT scan. According to the information sheet provided to participants, exposure to X-rays corresponds roughly to two to six months of natural atmospheric radiation received in France. Each volunteer receives an initial examination at enrollment, then a second scan one year later and a third three years after the first. Interim examinations may be scheduled when an anomaly requires close monitoring.
Images are analyzed by specialized radiologists, with the assistance of artificial intelligence tools designed to improve detection of anomalies. The program also contemplates the creation of a large anonymized image database to advance research and education.
The value of this experiment lies in its potential immediate benefit to participants. Unlike some organizational projects, IMPULSION leads to actual screening tests that could identify early-stage cancers. The study information notes that discovering a lung tumor at an early stage generally allows more effective management and substantially increases the chances of cure. Although this scenario remains relatively rare, a large European study cited in the document estimates that approximately 0.9% of participants could have a lung cancer detected early.
IMPULSION Program: Benefits Beyond Lung Cancer
The anticipated benefits of the program go beyond screening for lung cancer. The CT scans can also identify other tobacco-related conditions. Radiologists can detect signs of emphysema or chronic bronchitis, two respiratory diseases common among smokers. Abnormalities of the coronary arteries can also be detected. These are recognized markers of cardiovascular risk and can lead to preventive care.
The protocol also includes screening for signs of osteoporosis. This bone fragility, often silent, can be treated when diagnosed early, reducing the risk of future fractures. Additionally, all current smokers enrolled are offered specialized support for smoking cessation. Consultations with a tobacco-treatment specialist can be arranged, including remotely, to help participants quit.
The information document also notes that an optional sub-study allows, in certain centers, spirometry. This simple test measures respiratory capacity and aims to screen for chronic obstructive pulmonary disease (COPD), another common consequence of smoking.
AP-HP Seeks to Verify the Feasibility of a Future National Screening Program
If the potential benefits prove real, the project’s promoters emphasize that IMPULSION remains primarily a research endeavor. The data collected should help answer several essential questions: how to identify the at-risk populations, how to organize invitations, how to ensure follow-up on results, and what the cost of a nationwide rollout would look like. Researchers will also have to assess the constraints associated with screening. According to the participant information sheet, up to 15% of scans could lead to an additional follow-up exam. However, more than 95% of the small anomalies that are monitored in this way ultimately prove benign.
The study is planned to run for five years. Each participant will be followed for up to four years. At the end of this period, the results will give health authorities concrete data to decide whether a formal national program should be pursued.
The stakes are considerable. Lung cancer remains today one of the cancers most difficult to treat when discovered late. By demonstrating that targeted screening is both feasible and beneficial, IMPULSION could pave the way for a new strategy to combat this disease in France.
